Socket



Oct. 9, 1934. o, w. GREENE 1,976,492

SOCKET Filed June 3, 1951 Inventor-1 Olivgr Greene. by

Hi6 Attorney.

Patented Oct. 9; 1934 socxn'r 011 w. Greene,.Peaoe Dale; R. 1., allignor to General Electric New, York Company, a corporation of a pucituon n. a, 1931, Serial No. 541,816

' z (curs-ass) My invention relates to electrical sockets and more particularly to electrical sockets adapted for the reception of threaded plugs.

In general, the practice has been to secure a 6 metallic shell in the base of the body member of a socket by one rivet or bolt which at the same time serves to make electrical connection between the shell and .a conductor. When a plug is threaded into the socket its tip contact erfgages a center contact of the socket which is rigid or has a stop limiting its movement. In order to insure a good electrical contact between the tip contact of the plug and the center contact of the socket a certain amount of force must be exerted in threading the plug into the socket. The force used in making this contact must be resisted by the threaded metallic shell. This force isin a direction tending to pull the shell out oi! the sock-v et. Thus, when the shell is secured by a lone rivet or bolt, the shell is quite likely to break from its mooring if an excessive force is used in inserting the plug in the socket or after a plug has been inserted a number of times. Also, the shell is likely to be distorted in shape unless itis made of a comparatively heavy, grade of metal. Attempts to improve the securing oi the shell in the socket as by increasing the number 01 rivets, shrinking an insulating body member on the shell,

providing a divided body member with shoulders,

to engage the end of the shell or other means have all been met with increasedcosts of menu'- Iacture.

It is an object of my invention to provide a socket not requiring a metallic shell and which at the same time is adaptable for use with standard plugs; It is also an object of'my invention to produce an ele :trical socket of improved construction which will be of low cost of manufacture.

In accordance with my invention, the necessity of a threaded metallic shell is dispensed with as a means for threading theplug in the socket and making an electrical connection with the metallic shell on the plug. To provide means for threading the plug in the socket threads are molded in the insulating body member. To'make electrical connection with the shell on the plug a contact is provided withfingers extending from the base of the body member toward its mouth and outward substantially to the wall of the body member. The fingers of this contact are resilient and serve to engage the lower part of the shell on the 'plug as it is threaded in the socket. These fingers may be made sufiiciently long so they will engage the wall of the body member as they are forced back by engagement with the plug or the resilience of the fingers may be'relied upon alone to provide a sumcient contact pressure with the plug shell.

Referring to the accompanying drawing, Fi 1 is a view in cross section of myimproved socket and Fig. 2 is an exploded view or the socket inperspective. y

In Fig. 1, 10 indicates a socket made of ins lating material and having molded threads 11 adapted for the reception ofa standard plug. By the term plug' it is meant. to include a threaded attachment cap and the base of an incandescent lamp as well as what is ordinar y termed a plug. In the base of socket 10 connector 12, and contacti13 are secured. Contact 13 is provided with resilient fingers 13' which areadapted to engage the outside shell of a plug when it is inserted in socket 10. Terminal prongs 14 and 15 are provided to complete electrical connection with connector 12 and contact 13 respectively. Terminal prongs 14 and 15 are of the pin prick type and adapted to pierce the insulation of stranded conductors and ereby make ,electric connection with lthe stranded wires located in said conductors. Conductors 16 are shown connected to terminal prongs 1e and 15. To space the connector 12 and contact 13 apart and insulate them from each other, a washer?! of insulating material is provided. To assistin securing connector 12, con-. tact 13, and washer 17 in the base of the socket metalliccap 18 is rovided. To secure connector 12 and contact 13, washer 17 and metallic cap 18 in position inthe base of socket 10, a bolt 19 is provided with cooperating nut 20. The head ofbolt-19 also serves as a contact to engage thetip contact of a plug and is electrically connected to gmnector 12. To hold conductors 16 in engage- 11, By this arrangement when a plug is threaded into the socket 10 the tapered portion between the tip contact and the threaded portion Ofthe shell engages fingers 13' expanding them to;-conform with the tapered end of the shell. Bythis arrangement a considerable contact area is'provided between each of the fingers 13 and the tapered portion of the shell on the plug when threaded in the socket '10. This produces a large 1 base of socket and nut 20.threaded on the end of the bolt.- Nut 20 is tightened to hold the parts securely in position. Terminals'14 and are inserted through openings provided in-the base of the socket and apertures in the correspondingcontacts. The ends of the terminal prongs are expanded to prevent their removal and to make a good electrical connection with the contacts. To connect the socket with an electrical circuit the conductors 16 are laid'in the recesses 22 provided therefor and forced into engagement with the terminal prongs l4 and 15. Cap 21 is then threaded over the extension on the base of the socket into engagement with conductors 18;

The socket of my invention is of simple and rugged construction and easy to assemble. By dispensing with the necessity of a metallic shell, I have reduced the cost of manufacture and at the same time done away with one of the sources of difllculty. In the use, of. such devices, the contacts have no tendency to be pulled away from the securing means as a plug is threaded into the socket becauseof the fact that the body member itself resists the force exerted in threading the plug into the socket.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A socket comprising an insulating shell haveing molded threads to receive a threaded plug,

a contact member having a plurality of contact fingers extending longitudinally and radially from the base of the shell to the end of the molded threads and adapted to engage and conform with the tapered end of the shell contact-of a plug, a washer of insulating material, and a bolt securing said contact member and washer in the base of said shell and adaptedto engage the tip contact of a plfi.

2., A socket comprising an insulating shell having' molded threads to receive a threaded plug, a contact member seated in the base of said shell and having a plurality of resilient contact fingers extending longitudinally and radially from the base of the shell to the end of the molded threads and adapted to engage and conform with the of said shell and adapted to engage the tip contact of a plug.

I OLIVER w. GREENE. 

